Well Detectors with the Through-Hole Advantage

Well Detector Image

PGT germanium well detectors use the "through hole" technology to minimize microphonics and provide higher resolution performance. This is a true coax design, in which the crystal is less than 5 mm from the face of the endcap, and the sample can be placed deeper within the detector. The solid angle lost by this geometry is minimal for standard hole sizes and is more than compensated for by better detector performance, particularly at low energies, which translates to lower Minimum Detectable Activity values.

The closed-end well detectors manufactured by the competition are forced by that design to have a longer FET gate wire, as much as 6 inches or more, which significantly degrades resolution due to microphonics.

The bottom line is performance. PGT well detectors offer a lower MDA, faster counting rate and greater sensitivity. PGT believes that the through-hole design gives these well detectors the best performance.

The usual energy range is from 10 keV to 10 MeV, but the lower limit can be extended to 5 keV with beryllium or low-Z organic inserts. These detectors are ideal for use with sample changers. A representative efficiency curve is shown in Figure 1. With larger diameter holes, the efficiency may be somewhat less.

Features:

  • P-type high-purity germanium, with vapor-deposited gold center contact
  • Vertical dipstick cryostat
  • Standard 30-liter dewar
  • Aluminum endcap and well insert
  • Proprietary microphonic suppression system
  • RG-11 B/C resistive feedback preamplifier
  • 12-ft. bias, signal and power cables
  • Unlimited temperature cycling without loss of resolution

Options:

  • Custom well diameters up to 1.3"
  • Other crystal sizes, active volumes of 170 cc or more
  • Low-background NPR cryostat
  • Ultra-low background materials, such as low-background
  • aluminum well inserts and OFHC copper endcaps
  • Beryllium or low-Z organic well inserts
  • Other cryostat configurations
  • Can be mounted in a customized shield for low-background measurements
  • Low-power or transistor reset preamplifiers

Typical Applications:

  • Analysis of small samples for environmental monitoring and radiochemistry studies
  • Coastal and deep-water sediment research
  • Water and food pollution analyses
  • Geological and biological sample testing
  • Neutron activation analysis
Well Efficiency Diagram

IGW Well Detectors Product Specs

View and Print with Adobe Acrobat Well Detector Data Sheet